Cloud System Data Management Method and Apparatus

ABSTRACT

A cloud system data management method for alleviate a data leakage problem occurring when a user accessed by another user when a virtual data volume of the user is mounted to a virtual machine of another user includes creating a first virtual machine for a user and allocating a virtual data volume to the first virtual machine, setting an identifier of the virtual data volume as an identifier corresponding to a home identifier of the first virtual machine, determining, according to the identifier of the virtual data volume and a home identifier of a second virtual machine, whether the virtual data volume and the second virtual machine belong to a same user when the virtual data volume needs to be mounted to the second virtual machine, forbidding the virtual data volume to be mounted to the second virtual machine when they do not belong to the same user.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of International Application No.PCT/CN2014/089516, filed on Oct. 25, 2014, which claims priority toChinese Patent Application No. 201310511740.7, filed on Oct. 25, 2013,both of which are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present disclosure relates to the computer field, and in particular,to a cloud system data management method and apparatus.

BACKGROUND

In a cloud data storage environment, for a user, ownership of andcontrol rights for storage data are separated. An existing basicarchitecture of cloud computing includes a virtual machine and a virtualdata volume, where the virtual machine controls the virtual data volume.The virtual data volume, also referred to as a logical unit or a logicalvolume, is a data volume obtained by logically partitioning storagespace that belongs to a same user and that is in hardware storage space.An administrator may establish a correspondence between the virtualmachine and the virtual data volume using a cloud operating system(Cloud OS), and each virtual machine corresponds to one user.

The administrator has operation and maintenance rights, and may mount avirtual data volume to another virtual machine using the cloud operatingsystem. A logical unit number (LUN) is used as an example of the virtualdata volume. An LUN1 originally belongs to a virtual machine VM1, and avirtual data volume LUN2 originally belongs to a virtual machine VM2.The administrator can mount the virtual data volume LUN1 to the virtualmachine VM2 using the cloud operating system. As a result, a user of thevirtual machine VM2 can view data of the virtual data volume LUN1. Thereis a data leakage risk, when the virtual machine VM1 and the virtualmachine VM2 belong to different users.

SUMMARY

Embodiments of the present disclosure provide a cloud system datamanagement method and apparatus in order to reduce a data leakage riskthat is incurred when a virtual data volume is mounted to anothervirtual machine.

According to a first aspect, an embodiment of the present disclosureprovides a cloud system data management method, where the methodincludes creating a first virtual machine for a user and allocating avirtual data volume to the first virtual machine, where the firstvirtual machine has a home identifier, and the home identifier of thefirst virtual machine is used to identify a user to which the firstvirtual machine belongs, setting an identifier of the virtual datavolume as an identifier corresponding to the home identifier of thefirst virtual machine, determining whether a home identifier of thesecond virtual machine corresponds to the identifier of the virtual datavolume when the virtual data volume needs to be mounted to a secondvirtual machine, and allowing the virtual data volume to be mounted tothe second virtual machine when the home identifier of the secondvirtual machine corresponds to the identifier of the virtual datavolume, forbidding the virtual data volume to be mounted to the secondvirtual machine when the home identifier of the second virtual machinedoes not correspond to the identifier of the virtual data volume.

Based on the first aspect, in a first possible implementation manner,determining whether a home identifier of the second virtual machinecorresponds to the identifier of the virtual data volume furtherincludes determining whether the home identifier of the second virtualmachine and the identifier of the virtual data volume are identical.

Based on the first aspect or the first possible implementation manner ofthe first aspect, in a second possible implementation manner, the methodfurther includes setting an identifier of dynamic data of the firstvirtual machine as an identifier corresponding to the home identifier ofthe first virtual machine, and when the dynamic data needs to betransferred to the second virtual machine, determining whether the homeidentifier of the second virtual machine corresponds to the identifierof the dynamic data, and allowing the dynamic data to be transferred tothe second virtual machine when the home identifier of the secondvirtual machine corresponds to the identifier of the dynamic data, orforbidding the dynamic data to be transferred to the second virtualmachine when the home identifier of the second virtual machine does notcorrespond to the identifier of the dynamic data.

Based on the second possible implementation manner of the first aspect,in a third possible implementation manner, dynamic data is data inmemory of a virtual machine.

Based on the first aspect, in a fourth possible implementation manner,the method further includes setting the identifier of the virtual datavolume as a public identifier to indicate that the virtual data volumemay be mounted to any virtual machine before the virtual data volume isallocated to any virtual machine.

According to a second aspect, an embodiment of the present disclosureprovides a cloud system data management apparatus, where the apparatusincludes a creating unit configured to create a first virtual machinefor a user and allocate a virtual data volume to the first virtualmachine, where the first virtual machine has a home identifier, and thehome identifier of the first virtual machine is used to identify a userto which the first virtual machine belongs, a setting unit configured toset an identifier of the virtual data volume as an identifiercorresponding to the home identifier of the first virtual machine, adetermining unit configured to determine whether a home identifier ofthe second virtual machine corresponds to the identifier of the virtualdata volume when the virtual data volume needs to be mounted to a secondvirtual machine, and a processing unit configured to allow the virtualdata volume to be mounted to the second virtual machine when the homeidentifier of the second virtual machine corresponds to the identifierof the virtual data volume, or forbid the virtual data volume to bemounted to the second virtual machine when the home identifier of thesecond virtual machine does not correspond to the identifier of thevirtual data volume.

Based on the second aspect, in a first possible implementation manner,the determining unit is further configured to determine whether the homeidentifier of the second virtual machine and the identifier of thevirtual data volume are identical.

Based on the second aspect or the first possible implementation mannerof the second aspect, in a second possible implementation manner, thesetting unit is further configured to set an identifier of dynamic dataof the first virtual machine as an identifier corresponding to the homeidentifier of the first virtual machine. The determining unit is furtherconfigured to determine whether the home identifier of the secondvirtual machine corresponds to the identifier of the dynamic data whenthe dynamic data needs to be transferred to the second virtual machine,and the processing unit is further configured to allow the dynamic datato be transferred to the second virtual machine when the home identifierof the second virtual machine corresponds to the identifier of thedynamic data, or forbid the dynamic data to be transferred to the secondvirtual when the home identifier of the second virtual machine does notcorrespond to the identifier of the dynamic data.

Based on the second possible implementation manner of the second aspect,in a third possible implementation manner, the dynamic data is data inmemory of the first virtual machine.

Based on the second aspect, in a fourth possible implementation manner,the setting unit is further configured to set the identifier of thevirtual data volume as a public identifier to indicate that the virtualdata volume may be mounted to any virtual machine before the virtualdata volume is allocated to any virtual machine.

Based on the second aspect, in a fifth possible implementation manner,the apparatus further includes an acquiring unit configured to acquire acorrespondence between the second virtual machine and the user and sendthe correspondence to the determining unit.

According to the cloud system data management method and apparatusprovided in the embodiments of the present disclosure, when a virtualdata volume is allocated to a first virtual machine, an identifier ofthe virtual data volume is set as an identifier corresponding to a homeidentifier of the first virtual machine, and when the virtual datavolume needs to be mounted to a second virtual machine, it is determinedwhether a home identifier of the second virtual machine corresponds tothe identifier of the virtual data volume such that a virtual datavolume of a user is only allowed to be mounted to a virtual machine thatbelongs to the same user. This can alleviate a data leakage problem thatarises in the following case. An administrator mounts a virtual datavolume of a user to a virtual machine of another user, and consequentlydata of the user can be accessed by the other user.

BRIEF DESCRIPTION OF DRAWINGS

To describe the technical solutions in the embodiments of the presentdisclosure more clearly, the following briefly introduces theaccompanying drawings required for describing the embodiments. Theaccompanying drawings in the following description show merely someembodiments of the present disclosure, and a person of ordinary skill inthe art may still derive other drawings from these accompanying drawingswithout creative efforts.

FIG. 1 is an architecture diagram of a cloud operating system in anembodiment of the present disclosure;

FIG. 2 is a flowchart of a cloud system data management method accordingto an embodiment of the present disclosure; and

FIG. 3 is a structural diagram of a cloud system data managementapparatus according to an embodiment of the present disclosure.

DESCRIPTION OF EMBODIMENTS

The following further describes the technical solutions of the presentdisclosure in detail with reference to the accompanying drawings and theembodiments.

As shown in FIG. 1, FIG. 1 is an architecture diagram of an applicationsystem of a cloud system data management method according to anembodiment of the present disclosure. In a Cloud OS, a correspondenceneeds to be established between a virtual data volume and a virtualmachine, such as a correspondence established between a virtual datavolume LUN1 and a virtual machine VM1 when the LUN1 is allocated to thevirtual machine VM1, or a correspondence established between an LUN2 anda virtual machine VM2 when the virtual data volume LUN2 is allocated tothe virtual machine VM2. After a virtual machine is created for a userusing the Cloud OS and a virtual data volume is allocated to the user, asetting unit sets an identifier for the virtual data volume to identifya user to which the virtual data volume belongs. When an administratorwants to unmount the virtual data volume and mount the virtual datavolume to a target virtual machine, a determining unit determines,according to an identifier of the current virtual data volume, whetherthe virtual data volume and the target virtual machine belong to a sameuser. If the virtual data volume and the target virtual machine belongto the same user, the mounting is allowed. Otherwise, the mounting isforbidden. In this way, it is implemented that a virtual data volume ofa virtual machine of a user can be mounted only to another virtualmachine of the same user by the administrator, and is forbidden to bemounted to a virtual machine of another user. This can reduce a dataleakage risk incurred by mounting the virtual data volume to the othervirtual machine.

In a more specific example, the setting unit and the determining unitmay be two newly-added modules of the Cloud OS.

As shown in FIG. 2, based on the foregoing architecture, an embodimentof the present disclosure provides a cloud system data managementmethod, where the method includes the following steps.

Step 201: Create a first virtual machine for a user and allocate avirtual data volume to the first virtual machine that is created, wherethe first virtual machine has a home identifier, and the home identifierof the first virtual machine is used to identify a user to which thefirst virtual machine belongs.

The home identifier of the first virtual machine may be further anidentifier, such as a user name or a user identifier (ID), of the userto which the first virtual machine belongs.

The method for the administrator to create a virtual machine and avirtual data volume on a cloud server using the cloud operating systemis a general technology, and therefore, details are not describedherein.

After creating the virtual machine and the virtual data volume, theadministrator may allocate the virtual machine and the virtual datavolume to a specific user. It may be that only one virtual machine andone virtual data volume are allocated to a user, or multiple virtualmachines and multiple virtual data volumes are allocated to a user. Inother words, a user may have at least one virtual machine and at leastone virtual data volume. Virtual machines allocated to a user haveidentical or corresponding virtual machine home identifiers.

Step 202: Set an identifier of the virtual data volume as an identifiercorresponding to the home identifier of the first virtual machine.

Furthermore, after a virtual machine is created, an operating user maycreate a virtual data volume for the virtual machine using the Cloud OS.If the virtual machine has not been allocated to a specific user then,the system sets a public identifier, such as public (public is merely anexample and may be another identifier), for the virtual data volumeusing the setting unit in order to indicate that the virtual data volumecan be mounted to any virtual machine.

After the first virtual machine is allocated to a determined user, thesetting unit changes the public identifier of the virtual data volume toan identifier corresponding to the home identifier of the first virtualmachine. The identifier of the virtual data volume and the homeidentifier of the first virtual machine may be identical or may bepartially identical, or a corresponding mapping relationship may be setup between the identifier of the virtual data volume and the homeidentifier of the first virtual machine. For ease of operation, theidentifier of the virtual data volume is generally set to be identicalto the home identifier of the virtual machine, for example, as shown inTable 1.

TABLE 1

Similarly, if one virtual machine has multiple virtual data volumes, thesetting unit needs to set a corresponding identifier for each virtualdata volume.

Step 203: Determine whether a home identifier of the second virtualmachine corresponds to the identifier of the virtual data volume whenthe virtual data volume needs to be mounted to a second virtual machine.

When the operating user attempts to mount a current virtual data volumeto the second virtual machine, the determining unit of the cloudoperating system determines, according to an identifier of the virtualdata volume and the home identifier of the second virtual machine,whether the current virtual data volume and the second virtual machinebelong to a same user, where the determining unit may acquire, via anacquiring unit, a belonging relationship between the user and thevirtual machine using an interface.

For example, whether virtual machine home identifiers of the two virtualmachines correspond to each other may be determined by comparing thehome identifiers of the two virtual machines.

Step 204: If the home identifier of the second virtual machinecorresponds to the identifier of the virtual data volume, allow thevirtual data volume to be mounted to the second virtual machine.

Step 205: If the home identifier of the second virtual machine does notcorrespond to the identifier of the virtual data volume, forbid thevirtual data volume to be mounted to the second virtual machine.

According to the foregoing embodiment, when a virtual data volume isallocated to a first virtual machine, an identifier of the virtual datavolume is set as an identifier corresponding to a home identifier of thefirst virtual machine, and when the virtual data volume needs to bemounted to a second virtual machine, it is determined whether a homeidentifier of the second virtual machine corresponds to the identifierof the virtual data volume such that a virtual data volume of a user isonly allowed to be mounted to a virtual machine that belongs to the sameuser. This can alleviate a data leakage problem that arises in thefollowing case. An administrator mounts a virtual data volume of a userto a virtual machine of another user, and consequently data of the usercan be accessed by the other user.

In an embodiment, the identifier of the virtual data volume is used toidentify a user to which the virtual data volume belongs, and a homeidentifier of a virtual machine and an identifier of a virtual datavolume that belongs to a same user as the virtual machine are identical.

The determining unit determines whether the home identifier of thesecond virtual machine and the identifier of the virtual data volume areidentical. The virtual data volume is allowed to be mounted to thesecond virtual machine when the home identifier of the second virtualmachine and the identifier of the virtual data volume are identical. Thevirtual data volume is forbidden to be mounted to the second virtualmachine when the home identifier of the second virtual machine and theidentifier of the virtual data volume are not identical.

In a more specific embodiment, when the administrator allocates avirtual data volume LUN1 to a virtual machine VM1, the setting unitchanges an identifier of the LUN1 to a home identifier User ID1 of thevirtual machine VM1. When the administrator unmounts the virtual datavolume LUN1 from the virtual machine VM1, the LUN1 no longer belongs tothe virtual machine VM1, and the administrator mounts the virtual datavolume LUN1 to a virtual machine VM2, the determining unit checkswhether the identifier User ID1 of the virtual data volume LUN1 and ahome identifier User ID2 of the virtual machine VM2 are identical. Theoperation of mounting is allowed, when the identifier User ID1 of thevirtual data volume LUN1 and a home identifier User ID2 of the virtualmachine VM2 are identical. Otherwise, the LUN1 is forbidden to bemounted to the VM2, and execution of the administrator fails.

If the identifier of the virtual data volume is public, which indicatesthat the virtual data volume has not been allocated to any specificuser, the determining unit does not check a user identifier of thetarget virtual machine VM2 to which the virtual data volume is to bemounted, but directly allows the virtual data volume to be mounted tothe second virtual machine VM2. If the identifier of the virtual datavolume is not a public identifier, the determining unit needs to comparethe identifier of the virtual data volume with the home identifier ofthe second virtual machine that acts as the target virtual machine, tomake a determination.

In another implementation embodiment, it may be that no identifier isadded to the virtual data volume. When the administrator needs toperform a volume mounting operation, the cloud operating system queriesa user identifier of a virtual machine to which the virtual data volumeLUN1 originally belongs and a user identifier of the target virtualmachine VM2. If the two user identifiers are consistent, the volumemounting succeeds. Otherwise, the volume mounting fails.

There are other risks in the cloud operating system. For example, dataof a virtual machine needs to be backed up to another virtual machineduring virtual machine backup. If the two virtual machines belong todifferent users, it may also incur data leakage. Alternatively, if avirtual machine needs to be migrated from a physical server to a virtualmachine on another physical server, static data in the virtual machineand dynamic data in memory need to be copied to the to-be-migratedvirtual machine, and if the two virtual machines belong to differentusers, it may also incur a data leakage risk. Related preventivemeasures need to be taken for all data that may be transferred betweentwo virtual machines in order to avoid data leakage due to amisoperation.

Therefore, in another possible implementation embodiment, after thefirst virtual machine is created, the first virtual machine is allocatedto a determined user, an identifier of dynamic data of the first virtualmachine is set as an identifier corresponding to the home identifier ofthe first virtual machine, and when the dynamic data needs to betransferred to the second virtual machine, it is determined whether thehome identifier of the second virtual machine corresponds to theidentifier of the dynamic data, and the dynamic data is allowed to betransferred to the second virtual machine when the home identifier ofthe second virtual machine corresponds to the identifier of the dynamicdata, or the dynamic data is forbidden to be transferred to the secondvirtual machine when the home identifier of the second virtual machinedoes not correspond to the identifier of the dynamic data.

The dynamic data may be data in memory of the virtual machine.

For a specific method, reference may be made to the description of theembodiment in FIG. 2.

According to the cloud system data management method provided in thisembodiment of the present disclosure, an identifier of dynamic data isset as an identifier corresponding to a home identifier of a firstvirtual machine, and when the dynamic data needs to be transferred to asecond virtual machine, it is determined whether a home identifier ofthe second virtual machine corresponds to the identifier of the dynamicdata such that dynamic data of a user is only allowed to be transferredto a virtual machine that belongs to the same user. This can alleviate adata leakage problem that arises in the following case. An administratormounts dynamic data of a user to a virtual machine of another user, andconsequently data of the user can be accessed by the other user.

Correspondingly, an embodiment of the present disclosure provides acloud system data management apparatus that is used to implement themethod in the foregoing embodiments. As shown in FIG. 3, the apparatusincludes a creating unit 301 configured to create a first virtualmachine for a user and allocate a virtual data volume to the firstvirtual machine, where the first virtual machine has a home identifier,and the home identifier of the first virtual machine is used to identifya user to which the first virtual machine belongs, a setting unit 302configured to set an identifier of the virtual data volume as anidentifier corresponding to the home identifier of the first virtualmachine, a determining unit 303 configured to determine whether a homeidentifier of the second virtual machine corresponds to the identifierof the virtual data volume when the virtual data volume needs to bemounted to a second virtual machine, and a processing unit 304configured to allow the virtual data volume to be mounted to the secondvirtual machine when the home identifier of the second virtual machinecorresponds to the identifier of the virtual data volume, or forbid thevirtual data volume to be mounted to the second virtual machine when thehome identifier of the second virtual machine does not correspond to theidentifier of the virtual data volume.

In a first possible implementation manner, the identifier of the virtualdata volume is used to identify a user to which the virtual data volumebelongs, and a home identifier of a virtual machine and an identifier ofa virtual data volume that belongs to a same user as the virtual machineare identical.

The determining unit 303 is further configured to determine whether thehome identifier of the second virtual machine and the identifier of thevirtual data volume are identical, and the processing unit 304 allowsthe virtual data volume to be mounted to the second virtual machine whenthe home identifier of the second virtual machine and the identifier ofthe virtual data volume are identical, or the processing unit 304forbids the virtual data volume to be mounted to the second virtualmachine when the home identifier of the second virtual machine and theidentifier of the virtual data volume are not identical.

In another implementation manner, the setting unit 302 is furtherconfigured to set an identifier of dynamic data of the first virtualmachine as an identifier corresponding to the home identifier of thefirst virtual machine.

The determining unit 303 is further configured to determine whether thehome identifier of the second virtual machine corresponds to theidentifier of the dynamic data when the dynamic data needs to betransferred to the second virtual machine.

The processing unit 304 is further configured to allow the dynamic datato be transferred to the second virtual machine when the home identifierof the second virtual machine corresponds to the identifier of thedynamic data, or forbid the dynamic data to be transferred to the secondvirtual when the home identifier of the second virtual machine does notcorrespond to the identifier of the dynamic data.

In this implementation manner, the dynamic data is data in memory of thefirst virtual machine.

In another implementation manner, the setting unit 302 is furtherconfigured to set the identifier of the virtual data volume as a publicidentifier to indicate that the virtual data volume may be mounted toany virtual machine before the virtual data volume is allocated to anyvirtual machine.

The determining unit 303 is further configured to determine whether theidentifier of the virtual data volume is the public identifier when thevirtual data volume needs to be mounted to the second virtual machine,and the processing unit 304 allows the virtual data volume to be mountedto the second virtual machine when the identifier of the virtual datavolume is the public identifier, or the determining unit 303 determineswhether the home identifier of the second virtual machine corresponds tothe identifier of the virtual data volume when the identifier of thevirtual data volume is not the public identifier.

In the foregoing implementation manners, an acquiring unit may furtherbe disposed in the apparatus to acquire a correspondence between thesecond virtual machine and the user and send the correspondence to thedetermining unit 303.

According to the cloud system data management apparatus provided in thisembodiment of the present disclosure an identifier of the virtual datavolume is set as an identifier corresponding to a home identifier of thefirst virtual machine when a virtual data volume is allocated to a firstvirtual machine, and when the virtual data volume needs to be mounted toa second virtual machine, it is determined whether a home identifier ofthe second virtual machine corresponds to the identifier of the virtualdata volume such that a virtual data volume of a user is only allowed tobe mounted to a virtual machine that belongs to the same user. This canalleviate a data leakage problem that arises in the following case. Anadministrator mounts a virtual data volume of a user to a virtualmachine of another user, and consequently data of the user can beaccessed by the other user.

A person skilled in the art may be further aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, units and algorithm steps may be implemented byelectronic hardware, computer software, or a combination thereof. Toclearly describe the interchangeability between the hardware and thesoftware, the foregoing has generally described compositions and stepsof each example according to functions. Whether the functions areperformed by hardware or software depends on particular applications anddesign constraint conditions of the technical solutions. A personskilled in the art may use different methods to implement the describedfunctions for each particular application, but it should not beconsidered that the implementation goes beyond the scope of the presentdisclosure.

Steps of methods or algorithms described in the embodiments disclosed inthis specification may be implemented by hardware, a software moduleexecuted by a processor, or a combination thereof. The software modulemay be disposed in a random access memory (RAM), a memory, a read-onlymemory (ROM), an electrically programmable ROM, an electrically erasableprogrammable ROM, a register, a hard disk, a removable disk, acompact-disc read-only memory (CD-ROM), or a storage medium in any otherforms well-known in the art.

In the foregoing specific implementation manners, the objective,technical solutions, and benefits of the present disclosure are furtherdescribed in detail. It should be understood that the foregoingdescriptions are merely specific implementation manners of the presentdisclosure, but are not intended to limit the protection scope of thepresent disclosure. Any modification, equivalent replacement, orimprovement made without departing from the spirit and principle of thepresent disclosure should fall within the protection scope of thepresent disclosure.

What is claimed is:
 1. A cloud system data management method,comprising: creating a first virtual machine for a user; allocating avirtual data volume to the first virtual machine, wherein the firstvirtual machine has a home identifier, and wherein the home identifierof the first virtual machine is used to identify a user to which thefirst virtual machine belongs; setting an identifier of the virtual datavolume as an identifier corresponding to the home identifier of thefirst virtual machine; determining, according to the identifier of thevirtual data volume and a home identifier of a second virtual machine,whether the virtual data volume and the second virtual machine belong toa same user when the virtual data volume needs to be mounted to thesecond virtual machine; and forbidding the virtual data volume to bemounted to the second virtual machine when the virtual data volume andthe second virtual machine do not belong to the same user.
 2. The methodaccording to claim 1, further comprising allowing the virtual datavolume to be mounted to the second virtual machine when the virtual datavolume and the second virtual machine belong to the same user.
 3. Themethod according to claim 2, wherein determining, according to theidentifier of the virtual data volume and the home identifier of thesecond virtual machine, whether the virtual data volume and the secondvirtual machine belong to the same user comprises determining whetherthe home identifier of the second virtual machine and the identifier ofthe virtual data volume are identical, wherein the virtual data volumeand the second virtual machine belong to the same user when the homeidentifier of the second virtual machine and the identifier of thevirtual data volume are identical, and wherein the virtual data volumeand the second virtual machine do not belong to the same user when thehome identifier of the second virtual machine and the identifier of thevirtual data volume are not identical.
 4. The method according to claim1, further comprising: setting an identifier of dynamic data of thefirst virtual machine as an identifier corresponding to the homeidentifier of the first virtual machine; determining whether the homeidentifier of the second virtual machine corresponds to the identifierof the dynamic data when the dynamic data needs to be transferred to thesecond virtual machine; allowing the dynamic data to be transferred tothe second virtual machine when the home identifier of the secondvirtual machine corresponds to the identifier of the dynamic data; andforbidding the dynamic data to be transferred to the second virtualmachine when the home identifier of the second virtual machine does notcorrespond to the identifier of the dynamic data.
 5. The methodaccording to claim 4, wherein the dynamic data is data in a memory ofthe first virtual machine.
 6. The method according to claim 1, furthercomprising setting the identifier of the virtual data volume as a publicidentifier to indicate that the virtual data volume may be mounted toany virtual machine before the virtual data volume is allocated to anyvirtual machine.
 7. A cloud system data management apparatus,comprising: a processor; and a memory coupled to the processor, whereinthe memory having a plurality of instructions stored thereon, that whenexecuted by the processor, cause the processor to: create a firstvirtual machine for a user; allocate a virtual data volume to the firstvirtual machine, wherein the first virtual machine has a homeidentifier, and wherein the home identifier of the first virtual machineis used to identify a user to which the first virtual machine belongs;set an identifier of the virtual data volume as an identifiercorresponding to the home identifier of the first virtual machine;determine, according to the identifier of the virtual data volume and ahome identifier of a second virtual machine, whether the virtual datavolume and the second virtual machine belong to a same user when thevirtual data volume needs to be mounted to the second virtual machine;and forbid the virtual data volume to be mounted to the second virtualmachine when the virtual data volume and the second virtual machine donot belong to the same user.
 8. The apparatus according to claim 7,wherein the instructions further cause the processor to allow thevirtual data volume to be mounted to the second virtual machine when thevirtual data volume and the second virtual machine belong to the sameuser.
 9. The apparatus according to claim 8, wherein the instructionsfurther cause the processor to determine whether the home identifier ofthe second virtual machine and the identifier of the virtual data volumeare identical, wherein the virtual data volume and the second virtualmachine belong to the same user when the home identifier of the secondvirtual machine and the identifier of the virtual data volume areidentical, and wherein the virtual data volume and the second virtualmachine do not belong to the same user when the home identifier of thesecond virtual machine and the identifier of the virtual data volume arenot identical.
 10. The apparatus according to claim 7, wherein theinstructions further cause the processor to: set an identifier ofdynamic data of the first virtual machine as an identifier correspondingto the home identifier of the first virtual machine; determine whetherthe home identifier of the second virtual machine corresponds to theidentifier of the dynamic data when the dynamic data needs to betransferred to the second virtual machine; allow the dynamic data to betransferred to the second virtual machine when the home identifier ofthe second virtual machine corresponds to the identifier of the dynamicdata; and forbid the dynamic data to be transferred to the secondvirtual machine when the home identifier of the second virtual machinedoes not correspond to the identifier of the dynamic data.
 11. Theapparatus according to claim 10, wherein the dynamic data is data in amemory of the first virtual machine.
 12. The apparatus according toclaim 7, wherein the instructions further cause the processor to set theidentifier of the virtual data volume as a public identifier to indicatethat the virtual data volume may be mounted to any virtual machinebefore the virtual data volume is allocated to any virtual machine. 13.The apparatus according to claim 7, wherein the instructions furthercause the processor to acquire a correspondence between the secondvirtual machine and the user.
 14. A computer program product,comprising: a non-transitory computer-readable medium configured tostore computer executable instructions that, when executed by aprocessor, instruct the processor to: create a first virtual machine fora user; allocate a virtual data volume to the first virtual machine,wherein the first virtual machine has a home identifier, and wherein thehome identifier of the first virtual machine is used to identify a userto which the first virtual machine belongs; set an identifier of thevirtual data volume as an identifier corresponding to the homeidentifier of the first virtual machine; determine, according to theidentifier of the virtual data volume and a home identifier of a secondvirtual machine, whether the virtual data volume and the second virtualmachine belong to a same user when the virtual data volume needs to bemounted to the second virtual machine; and forbid the virtual datavolume to be mounted to the second virtual machine when the virtual datavolume and the second virtual machine do not belong to the same user.15. The computer program product according to claim 14, wherein theinstructions further cause the processor to allow the virtual datavolume to be mounted to the second virtual machine when the virtual datavolume and the second virtual machine belong to the same user.
 16. Thecomputer program product according to claim 15, wherein the instructionsfurther cause the processor to determine whether the home identifier ofthe second virtual machine and the identifier of the virtual data volumeare identical, wherein the virtual data volume and the second virtualmachine belong to the same user when the home identifier of the secondvirtual machine and the identifier of the virtual data volume areidentical, and wherein the virtual data volume and the second virtualmachine do not belong to the same user when the home identifier of thesecond virtual machine and the identifier of the virtual data volume arenot identical.
 17. The computer program product according to claim 14,wherein the instructions further cause the processor to: set anidentifier of dynamic data of the first virtual machine as an identifiercorresponding to the home identifier of the first virtual machine;determine whether the home identifier of the second virtual machinecorresponds to the identifier of the dynamic data when the dynamic dataneeds to be transferred to the second virtual machine; allow the dynamicdata to be transferred to the second virtual machine when the homeidentifier of the second virtual machine corresponds to the identifierof the dynamic data; and forbid the dynamic data to be transferred tothe second virtual when the home identifier of the second virtualmachine does not correspond to the identifier of the dynamic data. 18.The computer program product according to claim 17, wherein the dynamicdata is data in a memory of the first virtual machine.
 19. The computerprogram product according to claim 14, wherein the instructions furthercause the processor to set the identifier of the virtual data volume asa public identifier to indicate that the virtual data volume may bemounted to any virtual machine before the virtual data volume isallocated to any virtual machine.
 20. The computer program productaccording to claim 14, wherein the instructions further cause theprocessor to acquire a correspondence between the second virtual machineand the user.